The clock rate usually refers to the oscillating frequency of a central processing unit (CPU), random access memory (RAM) or the graphics processing unit (GPU) on your graphics card. This frequency is measured in the standard unit of hertz. For example, a typical modern desktop processor works at a speed of two to four gigahertz (billion hertz). Without going into unnecessary technical detail, this specification largely dictates the speed of that device, and higher frequencies typically mean that the device will perform better in a whole range of tasks, whether it be high-end gaming or anything else that requires a lot of system resources. There are also other factors that play a central role in performance, such as the number of processor cores in a CPU. For example, a quad-core CPU running at 3 gigahertz can provide up to four times more processing power than a single-core CPU running at the same speed. However, for the sake of this guide, we will only deal with clock speeds.
Overclocking refers to increasing the clock speed of a particular device beyond the speed it was manufactured to run at. Doing so will increase the rate of calculations that the device can complete, thus improving your computer’s performance. Overclocking is very popular among power users and anyone who wants to get every bit of potential out of their computers.
Benefits of Overclocking
Before we look at the significant drawbacks, we’ll take a look at the benefit of overclocking – increased performance. This is the only real reason to overclock your system, though some do it solely for bragging rights, even if they don’t need the extra power.
Overclocking will increase your computer’s overall performance, although the increase will only be noticeable in certain software and tasks. It won’t have a significant effect on things like loading speeds of Windows and video games, due to the fact that these rely largely on the data transfer speeds of your hard disk. It also won’t make much difference with things like multitasking, since this relies on how much system memory you have installed. However, where overclocking plays the most significant role for most users is gaming.
For example, your current system specifications, graphics settings and screen resolution may allow you to play a particular video game at an average frame rate of only twenty frames per second (FPS). At such a frame rate, performance may appear to stutter somewhat. Overclocking the processor on your graphics card may alleviate these issues and provide a significant frame rate increase. Overclocking the CPU will also have an impact, but it will be smaller in most games. This is due to the fact that the CPU is used to process calculations in overall system performance, whereas most video games are heavily reliant on the dedicated graphics chip for rendering 3D scenes. In games that have realistic physics effects (which are controlled primarily by the CPU), a CPU overclock will have a significantly greater impact.
Drawbacks of Overclocking
If you manage to successfully overclock your computer’s hardware, you will likely see a significant performance improvement in certain video games, other software and overall performance. However, some games and other software are relatively sensitive to overclocking, and issues may arise in some games rather than others. For example, just because you see a twenty percent increase in frame rate in one game doesn’t mean that you will in all other games.
There are many other drawbacks to overclocking, and it is this fact that turns most casual users away. For starters, you will need to provide additional cooling to get the highest performance increases. Unsurprisingly, as the component works harder, it will generate more heat. Because of this, the most common problem associated with overclocking is overheating. Overheating can cause graphical anomalies in video games and other applications that use 3D graphics. In the case of graphics cards, their anomalies, often called artifacts, usually come in the form of bright green polygons appearing randomly in the rendered 3D scene. Overclocking any component in your computer can cause system instability. While experimenting with overclocking, you will have to expect some random crashes and other issues. It will take some time to find a stable overclock. This fact applies no matter what sort of cooling you provide. Even the best hardware can only be pushed to a certain point, regardless of how much cooling you have.
Overclocking will also reduce the lifespan of your components. The higher the overclock, the shorter the lifespan of the component. In most cases, this is not really a concern, particularly since power users usually replace things like graphics cards and processors every two to three years anyway. However, there are no set rules to this. Sometimes, you might overclock your graphics card and happily run your games for a few weeks or months at what seems to be a stable overclock, only to find that it suddenly dies. If hardware is damaged due to overclocking, then it won’t be repairable. A burned-out component will need to be replaced, and if it was damaged due to overclocking, your warranty probably won’t be valid either.
There are exceptions to the rule regarding warranty. It is becoming increasingly common for some high-end CPUs and graphics cards to be factory-overclocked. Some hardware providers also provide components that they overclock and thoroughly test themselves, and then sell them overclocked and still under warranty. Other components come straight from the factory with an option to overclock them to a set speed. In the case of CPUs, such a setting will be found in the system BIOS (covered later on), and with graphics cards, the setting will be found in the graphics card control panel. However, if you are overclocking a component manually, and beyond the level that the manufacturer allows, you will almost certainly void your warranty.
Methods of Overclocking
The exact details of how to overclock a particular component vary enormously depending on your computer’s hardware configuration and the particular components themselves. The following broadly explains the various types and methods of overclocking. Before you begin, be sure to overclock only one component at a time. For example, only once you have found a stable overclock for your CPU should you start overclocking your graphics card or vice versa.
Overclocking the CPU
The processor is the brain of your PC, and it is the single most important component with regard to performance. This being the case, the CPU is also the most common item to be overclocked.
Before you overclock your CPU, it is highly recommended that you obtain a suitable system information tool to track important things like core temperatures and operating specifications. One of the best is CPU-Z. This free utility provides you with absolutely everything you need to know about your CPU, although it does not actually allow you to configure clock speeds and other options.
The CPU is normally overclocked using the BIOS. The BIOS (Basic Input Output System) is the top-level system setup utility. This software is installed on your computer’s motherboard, and it operates completely independently of the operating system (such as Windows). How you access the BIOS depends on your computer’s motherboard, but it is usually done by pressing a key within a few seconds of turning on your computer. You will usually see a message before Windows starts to load telling you which key to press to enter the setup utility. If you don’t see this notice, then your BIOS is probably configured to display the computer’s logo on boot. In this case, you may need to press Escape or another key to temporarily hide it. If you still cannot find the option, refer to the manual of your computer or motherboard.
Many high-end motherboards provide a more user-friendly overclocking feature in the form of an application which runs within Windows itself. If this is the case, you might not even need to use the BIOS at all. Regardless, how you change your CPU’s clock settings is entirely dependent on your motherboard model, of which there are literally hundreds. You can find your motherboard model in the “Mainboard” tab of CPU-Z. To find specific instructions on overclocking your CPU, refer to the specific manufacturer and model number.
Overclocking the RAM
RAM clock speeds, timings and other settings are relatively complicated. Some people experience better performance by increasing their memory speed, while others have more success by decreasing the memory latency (response time). Either option can cause severe system instability, so modifying such settings is generally not advisable, particularly since the performance gain is not likely to be nearly as impressive as it is when overclocking a CPU or graphics card. However, successfully overclocking your memory can help to resolve performance bottlenecks when overclocking other components in your system.
Most BIOS setup utilities provide advanced RAM settings designed for expert users. However, your motherboard may also provide some additional software or more user-friendly controls to help you to get more performance out of your memory sticks. You can find all of the performance information regarding your computer’s memory in the “Memory” tab of CPU-Z.
Overclocking the Graphics Card
In games, the most significant performance increases usually come from overclocking the graphics card. Due to the great popularity of graphics card overclocking, the process has largely been made much easier. Before you overclock your graphics card, be sure to download TechPowerUp’s free GPU information tool, GPU-Z. This is rather like CPU-Z, but only for graphics cards.
For AMD Radeon graphics cards, AMD provides its free AMD OverDrive utility. You can download it from the official AMD website. Once installed, you will find a new section of your AMD Catalyst Control Centre (accessible from the desktop right-click menu). Navigate to “Performance” and “AMD Overdrive.” You will need to acknowledge the disclaimer before being able to access the settings. Once you have done so, you can check the box beside “Enable Graphics OverDrive.” Here you can choose your GPU and memory speeds. They will initially be set at their default values. Try increasing both options by increments of about ten to twenty megahertz and then clicking “Apply.” Test out the new settings by running your favorite video game for a while. If you see any of the previously mentioned artifacts, decrease the speeds again. If you increase any setting too much, your system will likely freeze and need to be reset from the power point. In this case, the default settings should be restored. Other than that, feel free to experiment until you find a stable overclock.
Another useful tool for overclocking, and one which also works for nVidia graphics cards, is MSI Afterburner. Although it implies on the official MSI website that it is only meant for graphics cards manufactured by MSI, it should actually work with any modern graphics card including both nVidia- and AMD-based ones. This user-friendly utility provides five main settings alongside important live information on your graphics card’s performance and operating temperature. It also allows you to change the core voltage of your graphics card (provided that it is a voltage-unlocked model). You can also tell the program to automatically apply the new settings at system start-up, although you should avoid doing this until you have found the most stable overclock.
Overclocking a component makes it do more work in less time, and the higher the overclock, the more power the component will need. While most components can be overclocked without changing their default voltages, many power users find that increasing the amount of power allocated to the device allows for higher and more stable overclocks. However, many lower-end components are voltage-locked, in which case this setting cannot be changed. You will usually find voltage settings for your CPU and memory in the BIOS setup utility. For graphics cards, you should find these settings in various graphics overclocking utilities, such as MSI Afterburner mentioned previously.
Tips for Obtaining Higher and More Stable Overclocks
As is always the case with overclocking, your mileage will vary depending on a huge number of factors. It is also worth noting, that just because someone successfully managed to overclock the exact same processor, memory or graphics card as yours with the same cooling, this does not mean that you will have the same degree of success. No two components or configurations are ever the same. The following looks at some tips for obtaining higher overclocks from your components.
- Consider upgrading to a higher quality, more efficient power supply with a greater wattage if you are increasing the voltage settings of any components.
- While you will often be able to achieve modest overclocks with stock cooling, you will need to install better cooling for higher overclocks. There are many such third-party cooling systems available for CPUs. High-end memory sticks usually come with heat sinks preinstalled. High-end graphics cards usually come with excellent cooling systems which often cannot be replaced. Fortunately, stock graphics card coolers often give you plenty of headway for overclocking.
- Try cooling down your computer overall by installing additional case fans or even buying a new case that is specifically designed for power users.
- Be particularly careful if overclocking any laptop computer components. Due to the limitations of laptops, overclocking is rarely suitable for them.
- Finding the optimal overclocking setting can take many hours since you’ll need to stress-test your computer by running the most demanding games or applications. Benchmarking software such as FutureMark 3DMark is ideal for this purpose.
While overclocking clearly has its major benefits, it should not be taken lightly. Beginners should be sure to read up on their computer’s components and do their research thoroughly before taking the risks involved in overclocking. It cannot be emphasized enough that overclocking can cause hardware damage to your components, and if this happens, no amount of software tweaking will be able to help you. If you damage your hardware, it will need to be replaced. Fortunately, these risks are relatively low given the great improvements and failsafe features of many modern components. Above all, overclock with care and you will most likely find the results highly rewarding.